Study maps out reptiles’ ranges, completing the ‘atlas of life’

The study’s 39 authors, from 30 institutions around the world, pulled together data on the habitats of more than 10,000 species of reptiles.

They found little overlap with current conservation areas, many of which have used the numbers of mammal and bird species present as proxies for overall biodiversity.

In particular, lizards and turtles aren’t afforded much protection under current schemes.

The authors report that they’ve identified high-priority areas for conservation that protects reptile diversity, ranging from deserts in the Middle East, Africa and Australia, to grass- and scrublands in Asia and Brazil.

Across the swath of vertebrate lifeforms that inhabit Earth, scientists have a pretty good idea about where most of the known land mammals, birds and amphibians live. That makes identifying areas for protection where a lot of these animals live relatively straightforward, even if the details of actually protecting these places are far more complicated.

But plotting out the diversity of reptiles, which account for a third of all vertebrate species, has been a more elusive goal, leaving questions as to whether current conservation strategies protect this class of animals. Now, a global team of researchers reports that they’ve figured out where more than 10,000 reptile species live, completing an “atlas of life” that could guide future conservation efforts.

“Mapping the distributions of all reptiles was considered too difficult to tackle,” said co-author Shai Meiri, a zoologist at Tel Aviv University in Israel, in a statement. “But thanks to a team of experts on the lizards and snakes of some of the most poorly known regions of the world we managed to achieve this, and hopefully contribute to the conservation of these often elusive vertebrates.”

Until now, the siting of protected areas to safeguard biodiversity has relied on information about where the most plants, birds and mammals — and to a lesser extent, amphibians — live. To date, that includes 10,000 birds, 6,000 amphibians and 5,000 mammals. Without data on reptiles, planners often had to make educated guesses about the reptiles that a park or reserve might contain — in effect, using the biodiversity of other classes as a surrogate for reptilian diversity.

“This is not to say that the work done to date has been inaccurate,” said Richard Grenyer, a co-author of the paper and a biologist at Oxford University, in the statement. “[Based] on our knowledge at the time, conservationists have often made some really good decisions.”

A map showing the regions of the world that have gone up the most in conservation importance, now that scientists know where the reptiles are found. Image and caption by Roll et al., 2017.

The current study, conceived by Meiri 10 years ago and published on Oct. 9 by the journal Nature Ecology and Evolution, pulls together the work of 39 researchers from 30 institutions, cataloging the habitats of 99 percent of the living reptiles that we know about.

“[Now] conservation has the data and tools required to bring planning up to the same level as the businesses and governments who might have an eye on land for other uses,” Grenyer said.

Their findings reveal that reptiles aren’t protected very well by the current set of protected areas. Only about 3.5 percent of species’ ranges fall within these boundaries as defined by the IUCN. (That figure is lower for amphibians, at 3.4 percent.) In part, that’s because of where many reptile species live.

“Lizards especially tend to have weird distributions and often like hot and dry places, so many of the newly identified conservation priority areas are in drylands and deserts,” said Uri Roll, lead author and an ecologist at the Ben Gurion University of the Negev, in the statement. “These don’t tend to be priorities for birds or mammals, so we couldn’t have guessed them in advance.”

Proportionally, more lizard species live outside of these reserves than other reptiles. Turtles, too, aren’t afforded much security: The authors found that few turtle species benefit from having a minimum of 10 percent of their ranges protected.

Through their analyses, the team identified new areas in which this species diversity may be at risk, ranging from deserts in the Middle East, Africa and Australia, to grass- and scrublands in Asia and Brazil. These spots have potential for future conservation, in part because the land doesn’t cost as much since we wouldn’t have to give up a lot of farmland to set them aside.

But that’s not the only consideration, Grenyer said.

“On the one hand, finding vital areas in arid regions is a good thing because the land is fairly cheap,” he said. “But deserts and drylands are also home to lots of other modern activities, such as major irrigation projects, huge new solar power developments, and sometimes widespread land degradation, war and conflict.

“This makes them very challenging environment for conservationists to work.”

In freshwater ecosystems — critical habitats for turtles and crocodiles — the conservation calculus might also be different because these areas are also important to humans. This new information creates a picture that is more complicated, but one that Grenyer said is also more complete.

“Thanks to tools like our atlas, scientists can for the first time look at the terrestrial Earth in its entirety, and make informed decisions about how to use conservation funding,” he said.